add note to exclude runner from sandboxing assumptions

Author: rosieyohannan

docs/server-admin-4.2/modules/operator/pages/circleci-server-security-features.adoc

@@ -14,13 +14,19 @@ Security is our top priority at CircleCI. We are proactive and we act on securit
 
 [#encryption]
 == Encryption
-CircleCI uses HTTPS or SSH for all networking in and out of our service, including from the browser to our services application, from the services application to your builder fleet, from our builder fleet to your source control system, and all other points of communication. None of your code or data travels to or from CircleCI without being encrypted, unless you have code in your builds that does so at your discretion. Operators may also choose to bypass our SSL configuration or not use TLS for communicating with underlying systems.
+CircleCI uses HTTPS or SSH for all networking in and out of our service, including:
 
-The nature of CircleCI is that our software has access to your code and whatever data that code interacts with. All jobs on CircleCI run in a sandbox (specifically, a Docker container or an ephemeral VM) that stands alone from all other builds and is not accessible from the Internet or from your own network. The build agent pulls code via git over SSH. Your particular test suite or job configurations may call out to external services or integration points within your network, and the response from such calls will be pulled into your jobs and used by your code at your discretion. After a job is complete, the container that ran the job is destroyed and rebuilt. All environment variables are encrypted using link:https://www.vaultproject.io/[HashiCorp Vault]. Environment variables are encrypted using AES256-GCM96 and are unavailable to CircleCI employees.
+* From the browser to our services application.
+* From the services application to your builder fleet.
+* From our builder fleet to your source control system, and all other points of communication.
+
+None of your code or data travels to or from CircleCI without being encrypted, unless you have code in your builds that does so at your discretion. Operators may also choose to bypass our SSL configuration or not use TLS for communicating with underlying systems.
+
+The nature of CircleCI is that our software has access to your code and whatever data that code interacts with. With the exception of self-hosted runner, all jobs on CircleCI run in a sandbox (specifically, a Docker container or an ephemeral VM) that stands alone from all other builds and is not accessible from the Internet or from your own network. The build agent pulls code via git over SSH. Your particular test suite or job configurations may call out to external services or integration points within your network, and the response from such calls will be pulled into your jobs and used by your code at your discretion. After a job is complete, the container that ran the job is destroyed and rebuilt. All environment variables are encrypted using link:https://www.vaultproject.io/[HashiCorp Vault]. Environment variables are encrypted using AES256-GCM96 and are unavailable to CircleCI employees.
 
 [#sandboxing]
 == Sandboxing
-With CircleCI, you control the resources allocated to run the builds of your code. This will be done through instances of our builder boxes that set up the containers in which your builds will run. By their nature, build containers will pull down source code and run whatever test and deployment scripts are part of the codebase or your configuration. The containers are sandboxed, each created and destroyed for one build only (or one slice of a parallel build), and they are not available from outside themselves. The CircleCI service provides the ability to SSH directly to a particular build container. When accessing a container this way, a user will have complete access to any files or processes being run inside that build container. Only provide CircleCI access to those also trusted with your source code.
+With CircleCI, you control the resources allocated to run the builds of your code. With the exception of self-hosted runner, this will be done through instances of our builder boxes that set up the containers in which your builds will run. By their nature, build containers will pull down source code and run whatever test and deployment scripts are part of the codebase or your configuration. The containers are sandboxed, each created and destroyed for one build only (or one slice of a parallel build), and they are not available from outside themselves. The CircleCI service provides the ability to SSH directly to a particular build container. When accessing a container this way, a user will have complete access to any files or processes being run inside that build container. Only provide CircleCI access to those also trusted with your source code.
 
 [#integrations]
 == Integrations